1. Field of the Invention
The present invention relates to right vision equipment. More specifically, the present invention relates to systems for maintaining cooling systems for night vision equipment.
While the present invention is described herein with reference to illustrative embodiments for particular applications, it should be understood that the invention is not limited thereto. Those having ordinary skill in the art and access to the teachings provided herein will recognize additional modifications, applications, and embodiments within the scope thereof and additional fields in which the present invention would be of significant utility.
2. Description of the Related Art
The utility of night vision systems for military and commercial applications is currently well recognized. Many night vision systems use detectors which must be cooled to cryogenic temperatures for optimum performance. The cooling systems generally employ a working gas such as helium to achieve the desired low temperatures. However, helium has a tendency to leak because of the molecular, structure thereof. For optimum compression a purge of the chamber is required to assure that there is no moisture in the chamber which may solidify as ice during cooling and clog the minute passages of the device. After purging the chamber, the chamber is refilled with the working gas.
Conventional systems for purging and filling the cooling systems of night vision equipment are embodied in large, heavy, bulky, non-movable consoles. The consoles provide a workbench and gauges and other instruments for regulating the purge and fill operation.
Unfortunately, the size of the console is typically such that field maintenance of the night vision system is impractical. Thus, each system to be serviced must be removed from service and brought to a location having a purge and fill console.
Thus, there was a need in the art for a portable system for purging and filling the night vision cooling systems. This need has been substantially addressed by the invention of the above-referenced parent application entitled PORTABLE GAS PURGE AND FILL SYSTEM FOR NIGHT VISION EQUIPMENT of which the present application is a continuation-in-part. However, for safety reasons, a need remains in the art for a method for checking the pressure in the regulator of the subject unit before opening the outlet valve.
The need in the art is addressed by the present invention which provides a portable gas purge and fill system. The inventive system is disposed in a portable housing with gas inlet and outlet couplings. A safety valve is connected to the outlet of a pressure regulator. The safety valve maintains the pressure in the regulator below a predetermined safe threshold. In a specific implementation, the invention further includes a self-venting pressure regulator connected between the inlet and outlets thereof. A second gauge is included for measuring the pressure of the fluid contained in the source. First, second and third two-way valves are included. The first two-way valve is mounted between the second gauge and the pressure regulator. The second 9 two-way valve is located between the pressure regulator and the outlet. The third two-way valve is located between the outlet and the self-check mechanism. A conventional check valve is included for safety concerns.
As all of the components are disposed within a single housing, a safe, lightweight, portable purge/fill system is provided.